电化学法控制聚吡咯/α-磷酸锆/碳毡电极去除水中低浓度铅离子

Electrochemical Removal of Low Concentration Pb(Ⅱ) from Aqueous Solution Based on PPy/α-ZrP/PTCF Electrode

采用循环伏安法在水相中制备了电活性聚吡咯/α-磷酸锆(PPy/α-Zr P)有机-无机杂化膜,通过FT-IR、XRD、XPS对电活性PPy/α-Zr P杂化膜进行表征.将制备在碳毡(PTCF)基体上的电活性PPy/α-Zr P膜电极(聚吡咯/α-磷酸锆/碳毡电极,PPy/α-Zr P/PTCF)用于电控离子交换去除废水中的铅离子.通过对PPy/α-Zr P膜电极施加氧化还原电位来调节电活性组分PPy/α-Zr P的氧化还原状态,使废水中的铅离子能够快速置入和释放.在10 mg·L-1的Pb(II)水溶液中,膜电极对铅离子的去除效率为单纯离子交换的1.8倍,膜电极的吸附量为单纯离子交换的2倍,表明该膜电极在电控离子交换条件下对铅离子具有较强的去除效率和更高的吸附容量.吸附过程符合准二级动力学模型,电控离子交换的准二级吸附速率常数k2(0.6142 g·mg-1·h-1)明显高于单纯离子交换(0.2632g·mg-1·h-1).

A novel organic-inorganic hybrid film consisting of polypyrrole/α-zirconium phosphate （PPy/α-ZrP） was prepared in an aqueous phase by cyclic voltammetry method. It was proved by FT-IR, XRD and XPS characterizations that the electroactive PPyhx-ZrP hybrid film was synthesized successfully. The PPy/α-ZrP film electrode prepared on a porous three-dimensional carbon felt （PTCF） was used for removal of a low concentration of Pb（Ⅱ） ions from an aqueous solution by electrochemically switched ion exchange （ESIX）. A quick uptake and release rate of Pb（Ⅱ） onto the film electrode was obtained by adjusting redox state of the hy brid film. The removal efficiency and adsorption capacity of the PPy/α-ZrP/PTCF electrode for Pb（Ⅱ） were about 1.8 and 2 times higher than those of traditional ion exchange（IX）, respectively. Thus, the film electrode showed higher removal efficiency and ad- sorption capacity for Pb（Ⅱ） by ESIX. The adsorption kinetics of Pb（Ⅱ） could be described properly by the pseudo-second-order ki- netic mode. A greater pseudo-second-order rate constant of 0.6142 g·mg1· h-1 was achieved by ESIX, which was higher than that of 0.2632 g·mg-1·h-1 by IX.